Reducing tacheometer



Aug. -5 1924. 1,503,758

Y A. Kobus REDUCING TAGHEOMETER Filed Jan.' 26, 1924 3 Sheets-Sheet 1 Aug. 5 1924.

1,503,758 A. KNIG l REDUCING TACHEOMETER Filed Jan. 26, 1924 5 Sheets-Sheet 2 Patented Aug. 5, 1924,

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ALBERT KNIG, or JENA, GERMANY, AssrGNoa ro rss man Gaat zeiss, or JENA,

f GERMANY.

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Application filed January ducing Tacheonieter (forwhich I have filed an application in Germany February 2, 1923), of which the following is a specification.

The present invention relates to a reducing tacheometer containing a telescope which, in order to produceV double images, is provided with a .bisected `lens system whose both parts with an alteration of the angle of elevation of the telescopeautofV f matically undergo a displacement relatively Such a tacheometer has, e. g.,

the French patent specifito each other. been describedV in cat-ion 514,536.

rThe present invention `strives for providing forthe automaticreduction, i. e., for the automatic indication of the distance projected into the horizontal plane of a sight ing point not being on a level with the station of the tacheometer, the simplest possible r mechanisms. A particularly simplified device serving this purpose is'obtained if the two parts of the lens system (provided that the optical axis between the lens system and the horizontal axis is unbroken) be displaceably disposed Vrelatively to each other and parallelly to the horizontal axis ofthe telescope system (if therefore a horizontal staff be supposed), and if furthermore at least one of the two parts of the lens system be in contact with a plane surface, which with alterations of the angle of elevation brings about the relative displacement of both parts.

Another suitable device is obtained if at least one of the two parts of the lens system coacts instead of with a plane surface with a gearing constructed after the manner of a crank guide.

The invention is not only applicable to tacheometers of that kind with which a vfixed measuring angle is used, i. e., whereby to diHerent distances correspond different sections of the stati", Vbut also to tacheometers of the other kind with which the measuring angle forV horizontal sighting lines is variable in such away that. to all distances corresponds one and the same section of the staff.

If provision be made for the above mentioned plane surface, Daltllllly Sim- 26,192.4. Serial No. 688,883.

plified constructional form is obtained if it be parallel to the vertical axis of the telescope and intersects the horizontal axis of the telescope atl an angle deviating from 90o. Besides, by rendering this angle adjustable, there results a simplified arrangement for a tacheometer of that `kind with which to all distances corresponds one and the same section of the staff., In tacheometers of the other hind with which to different distances correspond different sections of the staff, one attains by rendering the said angle adjustable a simplified arrangement which affords, if the distance of the double images deviates froma whole multiple of the image ofthe unit of the graduation of the staff (if 'therefore two divisions of the staff do not coincide with each other), an exact reading of that fraction of the distance which correspondsto the fraction of this unit ad justed at any one time. However, it is also possible to attain an arrangementserving the same purpose without rendering the said angle adjustable. lt consists in this that in front of the upper or the lower half of the objective there is disposed aplane-parallel plate which is rotatable about an axis perpendicular to the horizontal axis and the optical axis of the objective.

Vhen using` the aforesaid plane surface another constructional form is attained by applying this surface-on a slide which is so coupled to` the telescope as to;v participate in rotations about the horizontal axis and which slide, on the telescope being rotated about the horizontal axis, undergoes a displacement perpendicular to the horizontal axis by means ofa gearing constructed after the mannerl of a crank guide.

AIn order that the distances read off will be directly the distances from the vertical axis of the telescope, it is advisable to select the distances ofthe telescope objective and of the hisected lens system from the horizontal axis and the'focal length of the objective in sucha manner that a virtual image ofthe'bisected lens system is produced by the objective at the locus of the horizontal axis.

1n the annexed drawing Figs. 1 and 2 show ina plan elevation and in a side eleva.- tion respectively a reducing tacheometer according to the presentinvention, Fig. 1 being a section on line 1 1 of Fig. 2 and Fig. 2 a section on thelne of Eig. l, Fig.

3 shows in a side elevation a second constructional example, Figs. 4 and 5 show in a plan elevation and in a side elevation respectively a third constructional example, Fig. 4 being a section on the line 4 4 of Fig. 5 and Fig 5 a section on the line 5-5 of Fig.

.4. Figs. 6 and 7 illustrate the essential parts of a fourth constructional example in a front elevation and a plan elevation respectively, Fig. 7 being a section on the line 7-7`of Fig. 6.

In the example shown in Figs. l and 2 there correspond to different distances different sections of the staff. On a carrying body a is supported rotatably about an axis X-X (which forms the vertical axis of the instrument) a carrier b, containing a fork b1. ln the latter there is rotatably supported a telescope o in such a way that its axis of rotation Y-Y (the horizontal axis of the instrument) perpendicularly intersects the vertical axis X-X. The telescope c contains an objective c1, an ocular c2, a glass plate provided with crossed threads and two semi-lenses 04 and c5, whose plane boundary surfaces are parallel to the horizontal axis Y-Y. The distances of the objective c1 and of the semi-lenses 04 and cj from the horizontal axis Y-Y are so chosen and the objective has such a focal length that the semi-lenses are virtually imaged by the 'objective into the locus of the horizontal. axis. Each of the semi-lenses is provided with two pivots c and c which are guided in the casing of the telescope c; the axes of the pivots c7 lie in the plane containing the horizontal axis and the objective axis. Each pivot c7 is provided at its free end with a ball es, laying against a plane surface of a plate cl, whereby a spring c, disposed between each semi-lens and the telescope casing land wound round the apertaining pivot c, causes a continuous Contact between the ball and the plate. Each plate cl is so disposed on the fork b1 that its plane surface do is parallel to the vertical axis XX and embraces with the horizontal axis Y-Y an angle which would be 90O lif the semi-lenses would be in their middle position, i. e. in such a position that their axes would coincide with the objective axis c1. Whilst the plate cl corresponding to the semi-lens c4 is fixed on the fork b1 by means of a set-screw (Z1, the plate d corresponding t0 the semi-lens is supported on the forli 1 with the aid of av shaft (Z2, which canY be rotated by means of a milled head d3, rotatably about the axis Z-Z of this shaft. The axis Z-Z is parallel to the vertical axis X-X and intersects the horizontal axis Y-Y.l On the shaft d2 is fixed a toothed wheel d* which Aengages in a toothed wheel e supported on the carrier Z) rotatably about the vertical axis X-X. This toothed whe-el e is rigidly vconnected to la drum el, whose axis coincides with the axis X-X and which coacts with an index b2, parallel to its axis and fixed on the carrier b. Upon the drain el is on the one hand traced a number of circular lines ef which are numdouble images, produced by the displace! ment of the semi-lenses out of their middle position, of the staff sighted at devlates from a whole multiple of the image of the unit of the graduation of the staff, to afford a more exact reading than the saine would be possible by estimating the respective fraction of this unit.

Prior to its use the tacheometer must be adjusted in such a way that the length of that part of the staff, by which in the image field the two double images are displaced relatively to each other, multiplied by a round figure (e. g., 100) indicates thegdistance, Thereby the distances s1 and 82 of the semi-lenses c4 and c5 out of their middle position have a certain, definite value and it must be seen to that that plate d, appertaining to the semi-lens c4, 1s clamped on the fork b1 according' to the value S1.

For using the instrument it should be set Y up in such a way that the vertical axis X-X is ina perpendicular position, and it is necessary to sight at the staff placed parallelly to the horizontal axis Y-Y- As a rule, the distance apart of the two double images will then not be equal to a whole multiple of the imageY of the unit of the graduation of the staff, i. e., two divisions of the staff will not coincide with each other. In this case one diminishes the displacement s2 of the semi-lens c5 from its middle position by rotating the appertaining plate d with the aid of the milled head Z3 until the distance of the double images is equal to a whole multiple, ascertains by the above multiplication the distance corresponding to this new displacement and adds to this distance that additional dista-nce, resulting from the adjustment of the index b2 relatively to the drum e?. Thereby that curve e3 holds good which passes through theY point of intersection of the index with the circular line e2, corresponding to the distance ascer tained. When measuring, the semi-lenses c4 and 05, owing to the sliding ofthe balls cg on the plates d, always undergo such a displacement that the distances read oftl are the horizontal distances.

The second Constr-notional example shown in Fig. 3 serves foroperating with one and the same section of the staff. It differs fromV that of the first constructional example by i the feature thatthe semilens of isrixed on the telescope casing c in such a Way as-to occupy the middle position mentioned in the description of the first example. The automatic reduction ofthe distance only takes place yet by means of a single plate d, appertaining to the semi-lens e5. The arrangement. made in the first example for the purpose of the exact reading of the fractions of the unit of the graduation of the staff has been dispensed with. A novel feature is represented by a scale b3 numberedaccording to distances which is fixed on the fork b1 coaxially with the shaft Z2 and coacts with an index (Z5 rigidly connected to the milled head d3.

When using the instrument it 'is necessary to adjust by rotating the plate cl by means of the milled head Z3 such a distance between the two double images that the i' one end of the one double image coincides With the other end of the other double image, whereupon the reduced distance of the staff can be read off on the scale b3.

The third constructional example shown in Figs. l and 5 is destined to operate with an invariable measuring angle, and therefore with different sections of the staff. As shown in the second example, the semi-lens c4 is fixed on the telescope casing but in such a Way that it is displaced out of its middle position by the amount s1. For reducing purposes it is only the semi-lens c5 than can be adjusted. For reducing the distance serves in thiscase a bevel Wheel f, which is supported on an arm co, fixed on the casing of the telescope c, rotatably about an axis parallel to the objective axis c1. This bevel Wheel engages on the one hand in another bevel Wheel b3 fixed on the fork l, on the other hand it carries a pivotV f1 engaging in the slit of a slide 010 rigidly connected to the pivot c7. Thereby the distance ofthe pivot f1 from the axis of rotation of the bevel wheel f is so chosen as l to be equal to the total of the'invariable displacement 81 of the Semi-lens c* and that displacement s2 of the semi-lens c5 out of the appertaining middle position each,`

Which appertains to the horizontal position of the telescope. J

During the use of the tacheometer the bevel Wheel f, adjustment being made to an angle of elevation deviating from zero, rolls over the bevel Wheel b3, whereby it experiences such a rotation about itsfown axis of rotation that in each case the angular amount of the rotation is equal to the corresponding angular amount of the rotation of the telescope about its horizontal axis Y-Y @Wing to the engaging of the pivot f1 in the slide 010 the semi-lens 05 undergoes such a displacement that the distance'between the double images is, as required, a measure for the reduced distance.

The fourth constructionall example shown in Figs. 6 and-'7 'is destined to be used with different sections of the staff. The optical. outfit is assumed to be the same as that in the above described constructional examples, i. e., for the semi-lenses the arrangement of the second example (vide Fig. 3) is based upon, that the one semi-lens (not shown) assumes 'its middle position and is fixed on the casing of the telescope 0 in this position. In order to reduce the distance on the horizontal plane there is supported on the telescope casing a square-rod g displaceable parallelly tothe objective axis, which rod carries a slide g1 in Whose slit engages a pivot b4'. This pivot is fixed on the fork b1 in such a Way that its axis is parallel to the horizontal axis Y-Y and lies with the latter in one and the same horizontal plane. The square-rod g carries a sliding piece g2, having a plane surface g3, against which is pressed by means of the spring 0 the ball 08 of the pivot c7 rigidly connected to the semi-lens c". The incline of the surface g3 to the horizontal axis T-Y and the distance of the pivot b4 from this axis are so chosen that the displacement, brought about with rotations of the telescope about its horizontal axis, of the square-rod g produces such a displacement of the semi-lens c5 that the distance between the double image is, as required, a measure for the reduced distance.

I claim: i

l. In a reducing tacheometer a telescope rotatablyv disposed about a horizontal axis, which is perpendicular to the optical axis of the telescope, the telescope comprising an objective and an ocular, two semi-lenses inserted in the path of the rays before the ocular and displaceable parallelly to the said horizontal axis, and mean for coupling the semi-lenses and the telescope so as to impart to the semi-lenses a relative displacement as the telescopeis rotated about the said horizont-al axis, these means comprising at least one plane Surface coacting with one of the semi-lenses. i

2. In a reducing tacheometer a telescope rotatably disposed about a horizontal axis, which is perpendicular to the optical axis of the telescope, the telescope comprising an objective and an ocular, tivo semi-lenses inserted in the path of the rays before the ocular and displaceable parallelly to the said horizontal axis, and means for coupling the semi-lenses and the telescope so as to impart to the semi-lenses a relative displacement as the telescope is rotated about the said horizontal axis, these means comprising at least one gearing constructed after the manner of a crank guide and coacting With one of the semi-lenses.

3. In a reducing tacheometer a. telescope rotatably disposed about a horizontal axis, Which is perpendicular to the optical axis of the teleseope,a1id about a vertical axis7 the telescope comprising an objective and an ocular, two semi-lenses, inserted in the path of the rays before the ocular and displace- `able parallell7 to the said horizontal axis, and means for coupling the semi-lenses and the telescope so as to impart to the semilenses a relative displacement as the telescope is rotated about the said horizontal axis, these means comprising at least one plane surface which surface is parallel to the said vertical axis and intersects the said horizontal axis at an angle deviating from 900, this surface `coacting with one of the semi-lenses.

4l. ln' a reducing tacheometer a telescope rotatably disposed about a horizontal axis, which is perpendicular. to the optical Vaxis of the telescope7 the telescope comprising an objective and an ocular, two semi-lenses inserted in the path of the rays before the ocular and displaceable parallelly to the said horizontal axis, means for coupling the semi4 lenses and the telescope so as to impart to the semi-lenses a relative displacement as the telescope is rotated about the said horizontal axisj these means comprising at least one plane surface, which surface is parallel to the said vertical axis and intersects the said `horizontal axis at an angle deviating from 900, and other mea-ns for varying this anglo, the said surface coacting with one of the semi-lenses.

5. ln a reducing' tacheon'ieter a telescope rotatably disposed4 about a horizontal axis,

one slide fitted to the telescope in such a way as to take part in rotations about the said horizontal axis, this slide having which is perpendicular to the optical axis` of the telescope, the telescope comprising an objective and an ocular, two semi-lenses inserted between the objective and the ocular and displaceable parallelly to the said horizontal axis, the distances of the objective and the semi-lenses from the said horizontal axis and the focal length of the objective being so chosen that a virtual image of the semi-lenses is produced at the locus of the horizontal axis, and means for coupling the semi-lenses and the telescope so as to irnpart to the semi-lenses a relative displacement as the telescope is rotated about the said horizontal axis, these means compris` ing at least one plane surface coacting with one of the semi-lenses.

7. In a reducing tacheometer a telescope rotatably disposed about a horizontal axis7 which is perpendicular'to the optical axis of the telescope, the telescope comprising an ob jective and an oculan two semi-lenses in serted in the path of the rays before the ocular and displaceable parallelly to the said horizontal axiss means for coupling the semilenses and the telescope so as to impart to the semi-lenses a relative displacement as the telescope is rotated about the said horizontal axis these means com )risinv at least oneV plane surface coacting with one of the semi lenses, a driving device adapted to 'impart to one of the semi-lenses a displacement independently of rotations of the telescope, and a scale and an index coacting with each other, the relative position' of which is controlled by the said driving device.

ALBERT KNIG. 

